The present invention relates to a method of manufacturing circuit boards, and more particularly to a method for manufacturing a plurality of identical circuit board units on a base plate at one time and replacing any defective circuit board unit with a good one without discarding the whole base plate.
Generally, a circuit board manufacturer produces circuits on base plates and supplies the base plates with circuits to electric appliance manufacturers. That is, the circuit board manufacturer""s work does not include the connection of electronic components to the circuit boards.
To mass-produce circuit boards, the circuit board manufacturer usually produces a plurality of small circuit boards on one big base plate to increase productivity. It is almost inevitable to have one or more defective small circuit boards mass-produced on the same one base plate. This small part of defective circuit boards often causes rejection of the whole base plate by the electric appliance manufacturer, resulting in serious loss to the circuit board manufacturer.
For the circuit board manufacturer, there are still many normal and usable circuit boards on the rejected base plate, and it would be a waste to discard the whole base plate. Such waste would result in increased manufacturing cost and poor competing ability of the manufacturer in markets.
A primary object of the present invention is to provide a method of manufacturing circuit boards that allows repair of a base plate having one or more defective circuit board units among a plurality of identical circuit board units formed on the base plate, so as to reduce manufacturing cost of mass-produced circuit boards.
To achieve the above and other objects, the method of the present invention mainly includes the steps of producing a plurality of identical circuit board units on a big base plate at one time, so that each circuit board unit is connected to the base plate only at several connecting joints; conducting a circuit test for each circuit board unit; if any defective circuit board unit is found, using a cutting module to cut the connecting joints between the base plate and the defective circuit board unit and removing the latter to leave a void on the base plate; using a trimming module to trim off the broken connecting joints; using a shearing module to cut a substitute and good circuit board unit from a spare base plate; and moving the substitute circuit board unit into the void on the base plate, and fixing it in place in the void with adhesive.